The first, in the Vita tripartita Sancti Patricii, states that on the borders of the future counties of Kildare and Offaly, the chieftain of that district, Failge Berraide, worshiped the pagan god Crom Cruach and vowed to avenge the god's destruction at Magh Slécht by killing Patrick.
[1] The second version, contained in the pseudo-historical prologue (PHP) to the Senchas Már, the High-King Lóegaire mac Néill (died 462) suggests dispatching an assassin to kill someone from Patrick's household in order to test his preaching of forgiveness.
[e] But the cause of the Poem[f] having been composed was as follows:[g]—Laeghaire ordered his people to kill a man of Patrick's people; and Laeghaire agreed to give his own award to the person who should kill the man, that he might discover whether he (Patrick) would grant forgiveness for it.
[8] Patrick then asked the Chief Ollam of Ireland, Dubhthach moccu Lughair to try the case, and this places the poet in a quandary because if he didn't impose an eric-fine this would seem an affront to Patrick, while if he did impose an eric, it would be an affront to God.
There is a link in the tradition that both men voluntarily sacrificed themselves in assisting the work of a greater saint, however it is generally accepted that they were two distinct persons.